Common residential and commercial refrigeration appliances rely on air-cooled condensers as part of the refrigeration cycle. In a conventional refrigeration system of this type, the condenser dissipates heat from the warm, high-pressure refrigerant fluid into the ambient air. Often a fan promotes this dissipative heat transfer by creating a flow of air over the surface of the condenser. In normal operation, sufficient heat is dissipated by the condenser in the high-pressure portion of the cycle so that when the fluid passes through the evaporator in the low-pressure portion of the cycle, its temperature is low enough to produce the required cooling.  
In many systems the compressor turns on intermittently, cycling the fluid and producing cooling only when necessary. If heat is not efficiently dissipated at the condenser, however, the cooling capacity of the evaporator will be reduced. This will cause the compressor to turn on more frequently and/or run for longer periods of time, shortening the life of the compressor and consuming more energy. Inefficient heat transfer at the condenser can thus increase the probability of compressor failure. Moreover, if the heat transfer efficiency at the condenser drops below a critical level, the evaporator will no longer be able to absorb enough heat to maintain the required refrigeration temperature, even if the compressor runs continuously. Therefore, in order to maintain food safety, prevent food poisoning, and reduce the spoiling of food or other perishable materials, it is critical that air-cooled condensers efficiently dissipate heat to the the ambient air outside the unit. 
Unfortunately, common refrigeration appliances often experience a significant degradation in condenser efficiency. For example, it is common for these appliances to be installed in locations where the ambient air has a high temperature, e.g., in hot kitchens, near ovens, grills, or ranges. Another common cause of condenser inefficiency is an obstruction of the airflow, e.g., by a plastic bag covering the condenser or blocking the air intake. If the fan fails, this will obviously reduce the airflow and condenser efficiency as well. It is also common for grease, dirt, lint, or some combination of these to collect on the surface of the condenser, creating an insulating layer that reduces the heat transfer to the ambient air. To make matters worse, several of these factors may be present at once, compounding the problem. 
When condenser inefficiency causes compressor failure or becomes so high that safe refrigeration temperatures can not be maintained, it is critical that the appliance be  repaired quickly to prevent the spoiling of perishable items. Replacing or repairing the appliance, however, can be expensive and time-consuming. 
To avoid the above drawbacks of air-cooled condensers, some commercial refrigeration appliances use water-cooled condensers instead. These systems, however, require a continuous flow of water to dissipate the heat from the condenser. This use of water increases the operating costs of the appliance and, in some circumstances, is not feasible when the water supply is limited (e.g., when water is available only from a well). Because of these disadvantages, water-cooled refrigeration appliances are often not affordable or practical, forcing people to continue to use common air-cooled refrigeration appliances. Consequently, there remains a need for a way to easily and inexpensively address the various problems associated with inefficient condensers in conventional air-cooled refrigeration appliances. 